Intestinal and Gastric Bypass

Jejunal bacterial flora, bile acid deconjugation, and breath hydrogen and methane excretion were studied in nine patients with end-to-side and nine patients with end-to-end jejunoileostomy and in eight patients with gastric bypass. Bacterial numbers did not differ significantly between healthy controls and any of the patient groups. Production of fermentation gases in anaerobic cultures supplemented with carbohydrates did not occur with jejunal secretions from healthy controls but was found in all intestinal bypass patients and half the gastric bypass patients. Bacterial bile acid deconjugation activity was significantly higher in end-to-side compared with end-to-end jejunoileostomy patients. In gastric bypass patients bile acid deconjugation was not significantly affected. Breath hydrogen after glucose ingestion was abnormal in six patients with end-to-side and three with end-to-end jejunoileostomy and in six of the patients subjected to gastric bypass. The highest values were found in the latter group. Breath methane, which is found in one third of a healthy population, was absent in all 18 patients with intestinal bypass, and this may indicate that a change occurs even in the colonic microflora after this operation. Both intestinal and gastric bypass may change the small-bowel microflora, with the greatest changes occurring after end-to-side jejunoileostomy and the least changes after gastric bypass.     

The Observed Effect of Gastric Bypass Surgery on Direct-acting Antiviral Treatment: a Case Report

Chronic hepatitis C virus (HCV) infection can be cured with treatment using direct-acting antivirals (DAAs). Although these drugs have been widely studied, information about certain special populations is missing. In this case report we describe a treatment-experienced patient with chronic HCV infection genotype 1b, treated with 150 mg/day simeprevir, 400 mg/day sofosbuvir, and 1,000 mg/ day ribavirin for 24 weeks, after a Roux-and-Y gastric bypass. At steady-state a pharmacokinetic curve was recorded of sofosbuvir, GS-331007, and simeprevir. Ribavirin trough plasma concentration (C_trough) was determined. The simeprevir area under the-concentration time curve (AUC_last) and C_trough were 9.42 h.mg/L and 0.046 mg/L, respectively. Compared to what was described in the literature, simeprevir exposure was low and therefore the simeprevir dose was increased to 300 mg/day. The increased dose of simeprevir was well tolerated and C_trough was 0.532 mg/L. Sofosbuvir AUC_last and C_trough were 0.63 h.mg/L and 0.0013 mg/L. GS-331007 AUC_last and C_trough were 21.02 h.mg/L and 0.35 mg/L. Ribavirin Ctrough was 2.5 mg/L. Sofosbuvir, GS-331007, and ribavirin exposure were comparable with levels described in literature. The patient achieved a sustained virological response twelve weeks after the completion of treatment.     

Perforated Duodenal Ulcer after Gastric Bypass Surgery

Gastric bypass procedures have been used widely in the surgical therapy of morbid obesity. Evidence exists that the bypassed gastric segment retains its ability to secrete acid. Acid-related ulceration and obstruction of the proximal gastric pouch after surgery have been well documented, but duodenal ulceration after gastric bypass has yet to be reported. We present the first reported case of duodenal ulceration and perforation after gastric bypass surgery for morbid obesity. This case demonstrates that acid-related gastroduodenal disease may occur in the bypassed gastrointestinal tract. Consideration should be given to this area in evaluating upper gastrointestinal bleeding and abdominal pain after gastric bypass. Because barium contrast studies may not adequately evaluate bypassed segments, and standard gastroscopes are not long enough to reach these areas, the use of longer endoscopes may be necessary to confirm the presence of gastroduodenal disease after gastric bypass.     

Longer-Term Physiological and Metabolic Effects of Gastric Bypass Surgery

Obesity is closely associated with the development of type 2 diabetes. Many strategies have been used in the past to combat these two conditions, but very few provide for stable and durable glycemic control. Bariatric surgery has emerged as a powerful tool for treating obesity and in over 70 % of cases provides a short-term cure for diabetes. While the acute metabolic effects of surgery are striking, it remains important for us to also consider the long-term effects. This review aims to summarize the chronic or long-term metabolic and physiological effects of Roux-en-Y gastric bypass (RYGB) surgery on pancreatic function, skeletal muscle and hepatic insulin sensitivity, and gastrointestinal remodeling. An increased understanding of the current state of research in these areas can provide the basis for stimulating further research that would contribute to new treatment and management strategies for obesity and diabetes.     

Chronic Parietal Cell Dysfunction after Reversal of Gastric Bypass

A middle-aged woman developed a postgastric bypass megaloblastic anemia which responded to treatment. She eventually had the bypass reversed 6 1/2 yr after it had been performed. Gastric parietal cell function has remained abnormal almost 3 yr after reversal of the bypass, as demonstrated by abnormal Schilling tests and high serum gastrin levels. Parietal cell antibodies in high titer, but no intrinsic factor antibodies, were demonstrated in her blood. These observations are interpreted as indicating the development of irreversible chronic atrophic gastritis probably related to reflux of bile into the bypassed stomach.     

An Unusual Complication of Gastric Bypass: Perforated Antral Ulcer

A perforated sealed antral ulcer was found at laparotomy in a 34-yr-old woman operated upon for chronic, severe, abdominal pain 3 yr after undergoing gastric bypass for morbid obesity. Since standard diagnostic studies, including barium and endoscopy are unable to demonstrate such a lesion, this article seeks to draw attention to a hitherto unrecognized complication of gastric bypass.     

Gastrojejunal Stricture After Gastric Bypass and Efficacy of Endoscopic Intervention

The Roux-en-Y gastric bypass procedure (RYGBP) is an effective treatment for morbid obesity. Anastomotic strictures are a common complication after RYGBP. This study examines the frequency of post-RYGBP gastrojejunal strictures (GJS), methods of evaluation, and the outcome of endoscopic intervention. Medical records of patients who had RYGBP for morbid obesity at our institution during four consecutive years were reviewed for patient demographics, medical comorbidities, surgical technique, and outcomes. Radiographic and endoscopic findings of those patients suspected to have GJS were noted. The impact of patient-related variables and surgical technique on risk of GJS, time to diagnosis of GJS, and treatment outcomes for GJS was determined. Of 888 patients, 503 had open RYGBP (57%) and 385 laparoscopic RYGBP (43%). Ninety-four patients (10.6%) underwent esophagogastroduodenoscopy (EGD) for possible GJS and 58 (6.5%) were found to have anastomotic stricture. Laparoscopic RYGBP was associated with increased incidence of GJS (43/385, 11.1%) compared with open RYGBP (15/503 or 2.9%, P = 0.0003). A total of 125 dilations were performed with an average of 2.2 dilations per patient. None of the strictures needed surgical revision. There were four perforations (3.2%) related to EGD. Mean time to diagnosis of GJS was 66.2 days. Eighty-seven of 94 patients underwent radiologic upper gastrointestinal (UGI) evaluation prior to EGD. UGI evaluation demonstrated a positive predictive value (PPV) of only 66% [95% confidence interval (CI) 52–77], and negative predictive value (NPV) of 83% (95% CI 65–93). Laparoscopic GBP is associated with increased risk of GJS. Endoscopic dilation of GJS is an effective treatment with minimal risk. Radiographic studies appear to have poor specificity for diagnosis of GJS and have a low positive predictive value. EGD should be performed in all suspected cases of GJS.